Can't argue with number 1.

Sarah Kerrigan, she goes from simple Ghost operative to the Overmind's favorite creation to Queen Bitch of the Galaxy. Also, from the Heart of the Swarm previews, it looks like she'll still kick ass in that game too.

1. Cutter Slade from Outcast.

I'm someone who loves Mario, Zelda, Samus, Gordon Freeman, Ryu, and Master Chief to death. But no one holds a candle to her.

Well he does kill Link from Ocarina of Time in order for the first Zelda game to happen so we can only assume he had his way with Zelda then. =P

-Luca Blight, Suikoden II -- "It took hundreds to kill me but I killed humans by the thousands. I am sublime! I am the true face of evil!"
-Yuber, also from the Suikoden series -- ""I simply desire a good fight with plenty of blood and the screams of the dying."
-Rayne, BloodRayne -- Loved the character, she was so sardonic and glib while killing Nazis left and right. She was like a really sexy vampire version of Spider-man
-Kratos, GoW -- It's like, you know, damn. It's not even a serious list without him.
-Orlandu, Final Fantasy Tactics -- One of the most overpowered video-game characters in history. His sword skill abilities were pure death. You could literally win most fights with him alone. I usually deleted him.

Wings of Liberty has essentially destroyed all my love for this character. I really hope Heart of the Swarm can reverse this, but I've lost a lot of faith in Blizzard recently.

I agree that WoL wasn't her best showing but she's so good in SC/Brood War that I still think she's totally badass.

EDIT: Damn it. I have to withdraw. I can't deny Luigi is by far the best.. 

Lucien Lachance of The Dark Brotherhood:

John Marston (He's probably my favorite character in video games of all time. I love the man so much):

Sam of Vanquish: